Diket.barisan aritmatika suku ke.9=35 Dan U4+U12=62. Tent. Rumus Un
Jawaban Terkonfirmasi
U9= 35
U4+U12=62.
a+8b =35
a+3b + a+11b =62
a+8b=35 x2
2a+14b=62 x1
substitusikan
2a+16b =70
2a+14b=62 sama sama di kurang
2b= 8
b= 4
2a +16(4)=70
2a=70-64
a=3
Un=a+(n-1)b
=3+(n-1)4
=3+4n-4
=-1+4n
Jawaban Terkonfirmasi
62 = (35-5b) + (35+3b)
62 = 70 – 2b
2b = 8
b = 4
maka, U1 = 35 – 8b = 35 – 32 = 3
Un = 3 + (n-1)4